On Thu, Jan 14, 2016 at 3:01 PM, Song Gao <[email protected]> wrote:
> Hello, > > I am profiling a finite element Navier-Stokes solver. It uses the > Jacobian-free Newton Krylov method and a custom preconditoner LU-SGS (a > matrix-free version of Symmetic Gauss-Seidel ). The log summary is > attached. Four events are registered. compute_rhs is compute rhs (used by > MatMult_MFFD). SURFINT and VOLINT are parts of compute_rhs. LU-SGS is the > custom preconditioner. I didn't call PetscLogFlops so these flops are > zeros. > > I'm wondering, is the percent time of the events reasonable in the table? > I see 69% time is spent on matmult_mffd. Is it expected in matrix-free > method? What might be a good starting point of profiling this solver? Thank > you in advance. > The way I read this, you are taking about 23 iterates/solve, and most of your work is residual computation which should be highly parallelizable/vectorizable. This seems great to me. Matt > > > Song Gao > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
